


Kinktober 2020 - Day 4: Incest (Fontfest, NSFW) DUBCON

by yastaghr



Series: Yastaghr's Kinktober 2020 [4]
Category: Undertale (Video Game)
Genre: Claiming, Claiming Bites, Dubious Science, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Vagina (Undertale), Exhibitionism, Extremely Dubious Consent, First Time, Incest, Kinktober, Kinktober 2020, M/M, Parent/Child Incest, Penis In Vagina Sex, Sibling Incest
Language: English
Status: Completed
Published: 2020-10-04
Updated: 2020-10-04
Packaged: 2021-03-08 01:26:14
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 950
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26817322
Author URL: https://archiveofourown.org/users/yastaghr/pseuds/yastaghr
Summary: S4N5 is just an experiment to his father now. But what about to his brother?
Relationships: Papyrus/Sans (Undertale)
Series: Yastaghr's Kinktober 2020 [4]
Series URL: https://archiveofourown.org/series/1947772
Comments: 4
Kudos: 41





	Kinktober 2020 - Day 4: Incest (Fontfest, NSFW) DUBCON

**Author's Note:**

> Still on Hiatus. Still waiting for insurance approval. Still in pain.

Sans (no, that’s not his name anymore, he’s S4N5 now) woke up to the feeling of someone goosing his coccyx. He tried to arch his back, but he couldn’t move. His arms, legs, skull, and ribcage were strapped down and he was gagged. He tried to relax and summoned his ecto-body. It wasn’t like this was the first time he’d woken up like this. Gaster was insatiable. Just so long as-

“Alright, Papyrus. Why don’t you show me what you’ve learned and name all the parts on the subject?” Gaster asked patiently. 

S4N5 shuddered. No, no, NO! He didn’t want his brother corrupted like this! Papyrus was innocent, he shouldn’t learn about sex by raping his brother in front of his dad! But there was nothing he could do about it, was there? He should just relax and accept this. At least his dad wasn’t “showing” his little brother about this on himself. That had been horrible for Sans. He would do anything to avoid that fate for his brother… including this.

S4N5 was forced to feel it as Papyrus poked, pinched, and stretched his way through naming every part of the female ecto Sans had summoned. Then he could do nothing but hear as Gaster undressed his brother and let Papyrus do the same thing for the male parts on himself. 

“Good job, Papyrus! Now, I’ve shown you videos of the next part. Do you think you can show me how you fuck him? Don’t worry about making him feel good, the subject we’re using can’t feel physical pleasure anymore,” Gaster lied. S4N5 shuddered. He could still feel it! He could still cum! Papyrus should learn how to please a female partner, shouldn’t he?

“UM… I THINK I’M STILL GOING TO TRY, DAD. I WANT TO PRACTICE FOR THE FUTURE AFTER ALL! AND… MAYBE HE’S REDEVELOPED IT?” Papyrus Said. S4N5 smiled. His brother was such a sweet kid.

“Alright, son,” Gaster conceded, “I could be wrong, after all. Now, are you ready to have sex for the first time?”

S4N5 watched as his brother nodded eagerly. “YES, DADDY! ARE YOU GOING TO WATCH TO MAKE SURE I DO IT RIGHT? I DON’T MIND IF YOU DO. I WANT TO GET IT RIGHT, AND YOU KNOW HOW TO DO IT… RIGHT?”

“Yes, son, that is correct. Now, daddy is going to touch himself while you do this, just like how I told you to touch yourself while watching the instructional material,” Gaster said. Geez, he was such a sleaze. S4N5 longed to wrap his hands around his father’s throat and strangle him. It probably wouldn’t stick. If being pushed into his own creation didn’t stick, why would that? It would probably make him feel better, though.

S4N5 was so caught up in his fantasy of dusting his rapist that he didn’t notice Papyrus was on top of him until he licked his neck. Sans shivered, but his shivers froze when Papyrus whispered in his ear, “I’M GLAD I’M DOING THIS WITH YOU, SANS. I’VE ALWAYS LOVED YOU MORE THAN AS A BROTHER. I JUST WISH I COULD DO IT WITH YOUR PERMISSION.”

S4N5- no, Sans found his cheeks warming with a blush. Papyrus… remembered him? Papyrus loved him? That- that was-

Inexperienced hands found their way to his clit and rubbed circles into it. Sans moaned and bucked his hips up into the touch. It was harsh but good. Papyrus grinned down at him and kept it up at the same time that he nibbled on Sans’ neck. He moved slowly down to his shoulder. By the time he reached it Sans was a wet, moaning mess. A coherent thought popped up in his fuzzy head. It said, i love papyrus and i want him to fuck me.

That thought unlocked the part of him that actually wanted to enjoy this. He tried to convey through his eye lights that he was okay with this to his brother, but Papyrus was lost in the feeling of pleasure he got from those moans, so Sans focused his energy on making more of them.

“You seem rather fond of playing with this one, Papyrus. Do you want him as your own?” Gaster asked, panting. Sans shuddered. He knew he wanted it, but Papyrus?

“YES, YES! CAN I CLAIM HIM, DADDY? PLEASE?” Papyrus shouted.

Gaster laughed. It was the most genuine laugh Sans had ever heard out of him. “Then go ahead, son. Take him as your own.”

That was all the permission Papyrus needed. He sunk his teeth into Sans at the same moment he sunk his dick into his pussy. Out loud, Sans moaned. Inside, he thought at his new mate, i love you, i love you, i love you so much!

Papyrus gasped, releasing his hold and staring Sans in the sockets. SANS? IS THAT YOU?

yes, paps, it’s me! i love you so much! thank you for claiming me, i’ve never wanted anything more than i wanted that in that second in my life! you can do anything you want to me, i’m yours and i give you my consent! Sans thought at his brother.

Papyrus grinned. THEN I’M GOING TO FUCK YOU, SANS. STARS, YOU FEEL SO TIGHT!

Then Papyrus launched into the fucking. He was uncertain at first, but it quickly built into a fast, hard rhythm that had the whole table creaking with his motions! Sans quickly lost track of each individual movement and let himself get lost in the sensations.

“That’s it, Papyrus. Fuck your mate! Leave him so full of your cum that he can’t walk!” Gaster moaned. 

The glint in Papyrus’ eye was truly wonderful to see. His voice promised, “I INTEND TO.”

**Author's Note:**

> You can find me on:
> 
> Pillowfort - https://www.pillowfort.social/Yastaghr  
> Tumblr - https://yastaghr.tumblr.com  
> Twitter - https://twitter.com/yastaghr * Most active


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